PURPLE BROTH

Broth base used for the biochemical differentiation of Shigella spp., based on carbohydrate fermentation according to ISO 2156.

Ingredients Gms / Litre
Proteose peptone 10.000
Beef extract 1.000
Sodium chloride 5.000
Bromo cresol purple 0.020
Final pH ( at 25°C) 6.8±0.2

Directions
Suspend 16.02 grams in 1000 ml distilled water. If desired add 5-10 grams of the carbohydrate to be tested. Heat if necessary to dissolve the medium completely. Dispense in tubes containing inverted Durhams tubes and sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Alternatively, to 900 ml of sterile and cooled basal medium aseptically add 100 ml of sterile 5 - 10% solution (final concentration 0.5 to 1 %)